Studies on the Filarial Prevalence among Dogs and the Mosquito Vectors in Nagasaki City, Western Japan : 3. On the susceptibility of Aedes albopictus and Culex pipiens molestus to the larvae of Dirofilaria immitis in Nagasaki City

Laboratory studies were conducted to determine the susceptibility of the females of two common mosquitoes to the larvae of Dirofilaria immitis. In the both species, mean number of microfilariae taken up by a female mosquito when fed on an infected dog is about the same as the expected number. In Aedes albopictus the rate of filariae discharged in droppings of mosquitoes is very low. However, a great part of the larvae having entered the Malpighian tubes of the mosquitoes are killed in the early stages of the development, therefore the experimental infection rate with the mature larvae is not so high. On the other hand, in Culex pipiens molestus the rate of filariae discharged in droppings is very high, but a great part of the larvae entering the Malpighian tubes are completed the development, and accordingly, the experimental infection rate with the mature larvae is not so low